172715891 has 2 divisors, whose sum is σ = 172715892. Its totient is φ = 172715890.

The previous prime is 172715887. The next prime is 172715897. The reversal of 172715891 is 198517271.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 172715891 - 2² = 172715887 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (172715897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86357945 + 86357946.

It is an arithmetic number, because the mean of its divisors is an integer number (86357946).

Almost surely, 2^172715891 is an apocalyptic number.

172715891 is a deficient number, since it is larger than the sum of its proper divisors (1).

172715891 is an equidigital number, since it uses as much as digits as its factorization.

172715891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35280, while the sum is 41.

The square root of 172715891 is about 13142.1417965262. The cubic root of 172715891 is about 556.9002751369.

The spelling of 172715891 in words is "one hundred seventy-two million, seven hundred fifteen thousand, eight hundred ninety-one".